The 1998 Gordon Research Conference on Prolactin will provide an outstanding forum for presentation and thorough critical discussion of progress in scientific areas directly pertinent to the functional, biochemical and molecular genetic aspects of prolactin (PRL). Sessions will cover the following topic areas: PRL in the mammary gland, PRL in the brain and behaviors, growth hormone and PRL actions in the whole body, neuroendocrine control of PRL, PRL/cytokine receptor functions, lactogens and reproductive functions, and immunoregulatory functions. The program for 1998 will be exceptional in that new mouse genetic models will be described in which each of the elements from the ligand through transcription factors have been genetically knocked out. The phenotypes of these models will certainly generate much discussion. A unique new feature of this conference will be a full session of short platform presentations that will be selected from submitted abstracts. This session will specifically focus on getting bright young trainees, and scientists early in their careers, to present their hottest findings. Poster sessions will be held for informal presentations open to all attendees. The conference organizers and discussion leaders will promote an environment in which broad participation in discussions and critique will occur. The speakers who have accepted our invitations represent a diverse spectrum of research interests, geographic regions, ages and include a good mix of men and women. The additional speakers who will be selected for the contributed papers session will add further to the diversity represented on the podium. The GRC on PRL has seeded numerous collaborative efforts over the years. In each of the past three years a symposium at the Annual Meeting of the Endocrine Society has been a direct descendent of a GRC session, and a full issue of the Journal of Mammary Gland Biology and Neoplasia was recently published as an outgrowth of presentations originally heard at the GRC. In this application we are requesting funds to partially defray expenses for trainees whose abstracts are accepted for presentation, and for a portion of the costs of speakers who have accepted invitations to make presentations.